Not sure anyone can be 100% correct in this case. I think everyone Will portray it together differently, regardless how right or wrong they might be.
I like the fact that Dave Cullen is so blunt, because much of what he says he says regardless of wether people like it or not. On the hand, when I see him talk he does Come off as a bit off simplistic.
There are other books about Columbine. I hate the media fuelled myths and I have very little liking that journalists and researchers etc have perpepuated myths. Such as the whole goth thing or revenge against the jocks. Its complete bollocks, yet somehow Larkin and Katherine Newman perpetuated these myths in their books. There were no targets(Larkin also confirm this, yet, IDK where this 'Eric was a goth' - thing came from. I know that this isnt true, because I participate in, and have friends that are goth). I dont think it makes it right to dismiss Larkins entire book, However.
The bullying stuff, imo, is really hard to know Where to place. On the one hand, we have withness accounts that it did happen to Eric and Dylan.
What irks me a bit about Jeffs version is that he says that they were the lowest of the low. I think he relies too much on Brooks Browns accounts. The book is good, though, for a number of reasons. Because, much like Dave Cullen, he spent years investigating the massacre, and he also offers much of insight information